Lew served as Obama’s chief of staff and as director of the Office of Management and Budget before taking the Treasury job.

Lew’s scrawl consisted of a series of loops that bore no resemblance to his name.

‘‘Jack assured me that he is going to work to make at least one letter legible in order not to debase our currency,’’ the president said during the White House ceremony at which he announced the nomination.

After just two months in the Treasury job, there are signs Lew’s practice is paying off. All the letters of Lew’s last name could be made out in his signature on the annual report of the Financial Stability Council, which came out in late April.

Lew still has time for more improvement before his name goes on the nation’s currency.